I have used M series cameras for a long time and they are nicely designed. The replacements that come closest to the M series in terms of handling are, I think, the MZ5 and MZ3, both superb modern cameras. These are a little more sophisticated than the MZ-M. All your lenses will be useable, although only in the exposure modes that they support. So, for example, an M series lens will work in aperture priority and manual modes.

If you want to use shutter priority mode you will need an A series or later lens with an "A" on the aperture ring.

If you can, I would advise sticking to Pentax lenses and you have a choice of rectilinear ultra wides, including: SMC Takumar 15mm f3.5 (very rare), 20mm f4.5, 24mm f3.5. The 20mm and 24mm also exist in the previous Super takumar series. These will obviously be second hand, but should be good. The 15mm is still available as a bayonet lens!

There are two types of polariser, linear and circular. You will need a circular polariser for use with autofocus cameras as the linear type upsets the autofocus system. I don't know if some exposure metering systems can also be affected.

In any event, TTL exposure should be fine but a separate meter will need to be adjusted to give 2.5 stops more exposure.

If the day was such that there was little polarised light around, or the polariser was not rotated so the best effect as seen through the viewfinder was obtained, then it is possible to get indifferent results.

If you choose a sunny day and experiment, rotating the filter to see the effect changing, don't forget also to rotate the filter every time you change your direction in relation to the light. You can't leave a polariser on one setting for all your shots.

Whenever I buy a second hand body I always fit new batteries, and then change them every 12 months regardless. I have never had batteries fail in use.

So far, in about two digital years we have had no problems with CF cards. I know others who have had cards that fail.

In general, use CF cards and not microdrives (no moving parts and better reliablility) and buy good, branded CF cards and not cheap offers, We use Fuji and SanDisk and they have all been fine. Treat them with care and hopefully the risk will be no higher than a film being lost in the post or damaged by the processor.

Nothing is 100% guaranteed.....

Hi Matt

Yes, I'm referring to Ansel Adams's Zone System. It's not half as complicated as is sometimes made out, and there are some simple ways it can be applied to good effect.

It's very worthwhile reading it up enough to understand the basics, but it doesn't need a huge tome to achieve that.

In slides, of course, the requirements are different in that the ultimate "sin" is to over-expose and have washed out areas. In this instance I tend to use centre-weighted metering and compensation based on experience. It doesn't take too long to assess if we routinely over or under expose and in what situations, and then correct our technique.

Hope that helps!

Hi Matt

There a couple of other ways around the problem of not finding a suitable mid-tone, and they depend upon a slight knowledge of the Zone System. This only applies to negative films, but if you find the darkest area you want a whisker of tone in and then give three stops less exposure, you should be about right. You can do the reverse with the lightest tone - but this time three stops more than the indicated exposure.

It works great for monochrome.

You will lose matrix metering, but to be honest whichever form of metering you use as long as you are familiar with its foibles its OK. More and more I find myself using spot metering.

The trouble with matrix maetering is that the camera is guessing what you are doing as defined in its algorithms. And I find it tends to over expose, but a different photographer taking different sorts of pictures might disagree!

You can use any Pentax K mount lens, manual focus or autofocus.

Do you need a zoom lens? If so, how about a modern light version such as the 28-70mm F4 FA which is small, light and excellent.

If you want a fixed focal length this depends upon your style of photography. Personally, if I were choosing only two fixed focal lengths they would be 24mm and 100mm. If only one, it would be 50mm. But that's me, and it might not suit you.

A final thought is that the SF7 is quite a heavy camera - one of the MZ series would be much lighter and more compact. An MZ5n with 28-70mm f4 lens would be an enormous improvement in terms of bulk and weight.

I think film scanners are capable of producing A3 prints without too much trouble. Our Nikon Coolscan IV produces 34.5 MB RGB files (2920 ppi) and the newer Coolscan V improves this to 4000 ppi.

Our 12 MP digital camera also produces 35 MB approx RGB files, and quality wise there does appear to be parity between the two.